1. Field of the Invention
The present invention is directed to the field of landscaping and blocks used to construct a decorative and functional border, curb or edge, and a method of manufacturing the blocks. The present invention may be readily retrofitted onto existing common edging materials or installed without use of such edging materials. The present invention also may be used as an edge restraint for use with paving stones or bricks or to provide decorative accent lines of contrasting color and texture in paver brick or stone installations.
2. Description of the Prior Art
Numerous methods and materials exist for the construction of borders, curbs or edging for landscaping or site improvement work. Such borders, edges or curbs serve several functions. First, they are decorative, and provide an orderly transition from a garden area to a lawn, or from a lawn to a sidewalk, etc. Second, they serve to separate different areas with different forms of plant life or other landscaping elements, thereby reducing maintenance requirements such as removing weeds, or trimming back plant life that would otherwise spread. Third, they can ease the process of lawn mowing by eliminating the need to hand trim the border areas of the lawn after mowing the main areas with a mechanical lawn mower.
One method for the construction of edgings for use around gardens or to divide sections of a garden involves the use of lengths of flexible metal or plastic edging materials that are anchored by digging a trench, placing the edging material, anchoring the edging material by driving spikes through it into the ground, and then filling the trench with dirt. Such methods are common and relatively inexpensive, but have several disadvantages. First, such materials do not have a natural, yet orderly appearance that is aesthetically pleasing in a landscaping application, having instead a man-made appearance. Second, such materials are not easily fixed in straight lines or measured curves due to their flexible nature. Third, such materials are susceptible to damage during lawn mowing, and do not provide a "mowing strip" which would allow the wheels of a lawn mower to follow the contour of the edging and lessen the need for hand trimming along the borders of the lawn. Fourth, such edgings are susceptible to heaving from frost action in climates where the ground freezes.
Another method of providing an edging is the use of numerous natural stones or man-made bricks or blocks. Such stones or bricks are installed by digging a shallow trench and placing the stones or bricks more or less continuously along the length of the trench. Such materials may also simply be placed on top of the ground without digging a trench. Natural stone has long been used for this application, but lacks the advantages of the present invention for several reasons. First, natural stone is typically of irregular shapes and requires labor intensive fitting of the natural stones along the border or edging, or costly cutting of the pieces to fit. This irregularity also makes natural stone difficult to accommodate lawn mowing, and precludes the placement of a mowing strip. Bricks or rectangular blocks may also be used for lawn edging using a similar installation techniques. Rectangular blocks do not lend themselves to the construction of curvilinear edgings, which are found in most landscaping applications, because they must be cut to avoid gaps that may allow penetration of grass roots or other plant life and to provide an orderly appearance.
Another method for forming an edging or border has been to pour a concrete edging in place. The disadvantages of this method are the expense and effort involved. To install such an edging, an adequate trench must be dug, then forms must be constructed laying out the line of the edging, then the concrete must be mixed, poured, and allowed to cure. Such edgings may also require the placement of expansion material filled joints, and are susceptible to cracking. Electrical wiring, as for outdoor lighting, cannot be readily installed in such structures, and if installed, cannot be maintained and inspected without destruction of the edging. In addition, such edgings are not readily removed in the event a change in the contour of the lawn or garden border is desired. Finally, such edgings do not provide a desirable natural appearance.
There have also been efforts to address some of these deficiencies in the prior art through masonry block designs and wet cast concrete designs that are meant specifically for use as an edging. These designs either are composed of single units that are capable of being laid in straight or curved lines, or multiple unit systems with curved and straight pieces. These products are produced on concrete masonry block or paving machines, or through pre-casting with numerous concrete forms, and are designed to allow the construction of curved edgings. These products, while an improvement over using a simple rectangular brick, do not provide a natural appearance due to their molded appearance from the manufacturing process. None of these edges have a mowing strip incorporated as part of its process design. Moreover, these designs cannot be retrofitted over an existing plastic or metal edging, and cannot accommodate electrical wires for installation of low voltage electrical landscaping lights.
Another field in which the present invention may be used is the field of curbs or edge restraints for surfaces that are paved with concrete or brick pavers or paving stones, or asphalt or concrete or other paving materials. An example of curbing is disclosed in U.S. Pat. No. 4,971,475. Such curbing suffers from many of the limitations discussed above regarding edging, e.g., lack of curvilinear construction without time-consuming and costly on-site cutting, susceptibility to heaving from freeze/thaw cycles, and inability for receiving electrical or other conduits.
Examples of paver stones are disclosed in U.S. Pat. Nos. 4,711,599 and 4,834,575. Typical paver edging restraints are plastic or metal strips fixed in a manner similar to the flexible edging materials discussed above. For similar reasons, the paver edge restraints are also difficult to fix in straight measured curves, and are susceptible to heave from freeze/thaw cycles. Additionally, such restraints do not provide a conduit for drainage or electrical lines.
Another aspect of the present invention is a method of manufacturing landscaping blocks having a groove and/or an angled end. Examples of masonry block molding are disclosed in U.S. Pat. Nos. 5,062,610 and 4,335,549. However, these patents do not disclose how to mold blocks having an angled end and a split top surface.
Accordingly, it is an object of the present invention to provide a landscaping block that is constructed with a groove or channel designed into the bottom surface of each landscaping block so that each block may be installed over prevalent existing edgings or installed with or without inexpensive connectors of a design disclosed herein.
Another object of the present invention is to provide a landscaping block that has a mowing or paver support edge on one or both sides of the unit to ease lawn mowing or to provide an interlock ledge for the placement of pavers and surface to secure with a spike. This ledge or lip allows efficient lawn mowing in the vicinity of the edging. This lip also serves as a base line for the screening off of the base material required for the installation of a layer of paving stones or bricks and provides an edge structure that assures the integrity of the base layer of sand commonly used underneath the paving stones.
Another object of the present invention is to provide a landscaping block such that the uppermost surface of each unit has a natural stone appearance.
Another object of the invention is to provide a landscaping block with sides that taper from the lip to the bottom along the block's length to better resist the effects of frost heave, and to ease installation.
Another object of the invention is to provide a landscaping block with means to accommodate the passage of electrical wiring for outdoor lighting.
A still further object of the invention is to provide a landscaping block that combines some or all of the elements of each of the various objects disclosed above.
Another object of the present invention is to provide a landscaping block system that is constructed of blocks that are capable of forming either straight or curved edges, curbs or borders and incorporate some or all of the elements of each of the objects disclosed above.
Another object of the invention is a method of manufacturing landscaping blocks vertically in a mold and in pairs, where the top of each block has a split surface.
These and other objects of the present invention will become apparent with reference to the drawings, the description of the preferred embodiment and the appended claims.